This invention relates to high-rise building fire rescue, specifically to an apparatus and method to rapidly deploy a suspension cable from an upper floor of a high-rise building to the ground. The suspension cable would be used to facilitate building occupant evacuation or firefighter access to an upper floor. Several patents outline evacuation or access mechanisms once the suspension cable is installed. An evacuation mechanism example is U.S. Pat. No. 2,088,514 granted on Jul. 27, 1937 to Glover. An access mechanism example is U.S. Pat. No. 4,256,199, granted to Sellards on Mar. 17, 1981.
Present art methods for high-rise building cable positioning fall into four areas. None are in general use due to limitations, which will be outlined.
The gravity drop method is disclosed in U.S. Pat. No. 734,230 granted on Jul. 21, 1903 to Hillier. This gravity drop method requires a length of cable to be positioned at the top of the building and released. The limitation to this method is the requirement that the building have no mid-height roof line. The cable would stop at this roof line and not reach the ground. Another gravity drop limitation is wind buffeting the cable resulting in uncertainty of grasping the cable end at ground level.
The cannon shoot method is disclosed in U.S. Pat. No. 1,069,088 granted on Jul. 29, 1913 to Taylor. A method is used to propel the cable from the ground to the building upper floor. The cable and grappling hook would arch toward the building. The major limitations of this method are wind buffeting and uncertainty of the cable end properly engaging the building. Due to weight limitations in flight, the cable would need to be very light in weight. Thus, the cable strength would also be a limitation.
The helicopter method is outlined in U.S. Pat. No. 4,256,199, granted to Sellards on Mar. 17, 1981. A limitation of this method is the inability to perform the helicopter flight under poor conditions such as wind or reduced visibility due to smoke or fog. Other limitations include quick response of an available helicopter and sufficient operator skill in performing the cable transfer.
A last method is to have the cable be permanently installed as outlined in U.S. Pat. No. 5,038,536, granted to De Mendoza Sans on Aug. 13, 1991. A limitation of this method is aesthetics. Multiple cables angling down from a high-rise building would detract from the building architecture. Due to limited space, a permanent cable attachment may not be possible. In a city with close proximity of high-rise buildings, the multiple permanent cables would overlap causing clearance issues. Also, an existing street may be the only option for the lower attachment point. These limited space conditions would necessitate a temporary cable method.